1. Field of the Invention
This invention relates to an optical input device for a digital computer or terminal and, more specifically to an input device formed of optical fibers and/or light wave guides which receives an input light beam and indicates the position of the light beam thereon in two or three dimensions.
2.Brief Description of the Prior Art
Fiber optic input devices for use in conjunction with digital computers or terminals are known in the prior art. A typical example thereof is shown in U.S. Pat. No. 4,911,527 of Felix Garcia, Jr. et al. which is incorporated herein by reference, wherein a fiber optic device receives a light beam from a movable light source relative to the input device to provide input signals to a terminal. The device includes a single plane of parallel, clad optical fibers forming columns of a matrix and another similar single plane of parallel, clad optical fibers forming rows of a matrix, the two planes being placed together to form the matrix. The cladding is removed from the top surface of each fiber to form a window therein to permit the light beam to directly contact the selected window in the column plane and to permit the light beam that passes the column plane optical fibers to enter the window of the row plane. Light sensors are connected to the ends of the optical fibers in both the column and row planes so that a first signal is generated indicating a column position and a second signal is generated indicating a row position, thereby fixing the intersection of the column and row optical fibers at the point where the light beam impinges. At least one more similar single vertical position plane may be positioned adjacent and below the row plane. This vertical position plane has at least one light detector connected to the ends of the optical fibers and provides a signal responsive to the light beam that passes the column and row planes indicative of the vertical position of the light source with respect to the input device.
A further prior art fiber optic input device is set forth in Ser. No. 07/457,439, filed Dec. 27, 1989 of Felix Garcia, Jr. et al. for Device For Three Dimensional Tracking Of An Object, the contents of which are incorporated herein by reference. This application discloses a device for tracking an object in three dimensional space having a fiber optic sensor array which includes a row plane and a column plane, each plane having a plurality of parallel optical fibers bonded together. A row detector is coupled to the ends of the fibers comprising the row plane and a column detector is coupled to the ends of the fibers comprising the column plane, the row and column detectors being coupled to a decoder circuit. A pair of beam generators are affixed to the object and are each operable to transmit beams which terminate on the fiber optic sensor array. By determining the points of incidence of beams, the decoder circuit determines the position of the object in three dimensional space.
In each of these devices, a system of optical sensors is required to be secured to the optical fibers to provide appropriate readouts therefrom.